1. Technical Field
The present disclosure generally relates to the field of power production and control of same, as well as telematics, and is particularly suited for use in locomotives, for example as a retrofit to the same, as well as for other transportation and non-transportation uses.
2. Description of the Related Art
Diesel electric locomotives use engines as prime movers to drive traction alternators. These alternators generate AC and rectified to DC power which is directed to drive motors attached to the axles of the rail mounted vehicle (i.e., locomotive). The drive motors, also referred to as traction motors, are geared directly to the axles, and the rotation of the drive motors provides the force necessary for traction.
Locomotives are configured and designated by the number of powered drive axles they were manufactured with. The number of drive motors is a designation used by US and International locomotive manufacturers. For example, locomotives built in the US by General Electric (GE) are divided into two classes, a “C” class, which has 6 powered drive axles, and a “B” class, which has 4 powered drive axles. Electro-Motive Division of General Motors (EMD) has also produced a number of different horsepower models of locomotives, all of which are divided into 6 axle Special Duty (SD) models or 4 axle General Purpose (GP) models. Internationally models are all listed as either 6 axle CO-CO models, or 4 axle BO-BO models. The model designation is also associated with a respective distinct wiring and control system to accommodate the number of drive axles in the design. Control system and wiring schematics are not interchangeable across the model ranges of locomotives, even those of a common manufacturer.
Traditionally, locomotive repower systems are purpose built to the number of drive motors in the locomotive platform. Even if the original engines or alternators are replaced in kind, upgraded or modified, such replacements, upgrades or modifications are purpose built to the specific locomotive platform.
Control systems have been designed to allow a man-machine interface to operate a locomotive directionally, provide throttle and braking commands, and pass these commands to other locomotives when used in duplicity (i.e., consist). The operator initiates a command that is relayed though electrical relay logic, or on later model locomotives via microprocessor commands, to cause the traction alternator to generate power. The prime mover or engine responds to the throttle command causing the alternator or generator to create energy by increasing power (RPM's) or, alternatively, slowing down and reducing the power, according to the operators command.
Locomotives are designed using an eight step throttle scheme (called notches in the United States). Nearly all locomotives employ this eight notch power system when operating in the throttle setting. The throttle is divided into eight distinct power settings, notch one through eight not inclusive of idle. Each of the throttle settings has a horsepower assignment, which varies by model, available horsepower and other criteria established by the manufacturer or owner. If the operator moves the throttle from idle to notch one, the engine speed (i.e., revolutions per minute or RPM) increases to the manufacturers specified RPM, driving the generator or alternator to produce a specified level of energy. Moving the throttle up through the notches causes the engine speed or RPM to change, “generating” more energy to deliver to the drive motors.
Locomotives typically employ two types of braking, a primary braking function achieved via air brakes (i.e., pneumatic braking) and a secondary braking function achieved via dynamic braking. The braking setting for dynamic braking is distinct from the throttle setting, and in contrast thereto, is more of a rheostatic braking command.
The control system monitors the drive motors based on the following criteria: Generator Output=Traction Motor Input. Thus, the number of drive motors is intrinsic to the overall design and operation of the control system. The delivery of energy to traction motors is controlled via the control system which increases or decreases alternator/generator output accordingly.
In summary, on known locomotive or rail mounted vehicles, each locomotive is built using a standard throttle notch horsepower setting, and that horsepower is delivered to the exact number of drive motors for which the control system was designed to monitor, either through relay logic or by a microprocessor. The control system will only function for the model intended.